Validation and Interobserver Reliability of a Simple Ultrasound Score for Crohn's Disease

Crohn's disease (CD) is a chronic inflammatory disease in the gastrointestinal (GI) tract. It is characterized by an alternating course between remission and relapse, which necessitates subsequent adjustments in medical therapy. Thus, it is important to have suitable tools to assess disease activity, and currently the reference standard is using ileocolonoscopy. However, ileocolonoscopy causes major patient discomfort and due to logistic reasons, it cannot be performed on a regular basis. High frequency ultrasound (US) is a potentially useful tool to evaluate changes in disease activity in affected bowel segments. Although there are some studies using US in CD patients to construct ultrasonographic scoring systems, there are no validated scores in daily clinical practice. In a recent study by Nylund et al, we used multiple linear regression to select which simple conventional ultrasound parameters that should be included in an ultrasound scoring system (Simple Ultrasound Score of Crohn's Disease (SUS-CD)) using endoscopy as a reference (unpublished data). In this study, we aim to validate this scoring system using an endoscopic score (Simple endoscopic activity score for Crohn's disease (SES-CD)) as reference standard and to assess interobserver variability. The scoring system might be a useful supplement to endoscopy to follow up CD patients.